What can be done to repair generators?
Generators come in all different shapes and sizes and can run on a wide variety of fuel types which can include Diesel, Gas, Biofuel and HVO (hydrogenated vegetable oil). Unless maintained correctly they can fail when you least expect and cause immeasurable amounts of business disruption. All manufacturers will provide a specified maintenance regime with the equipment when you purchase it, and it is essential that the specified maintenance is carried out by qualified personnel at the specified intervals. Failure to comply with the recommended maintenance may not only cause it to breakdown but also invalidate any warranty the manufacturer provides.
Depending on the type, make and application different generators require different levels of care, some of the factors that can determine maintenance intervals can be things such as-
- Engine Run Hours
- Poor Performance
- Equipment Application
- Operating Environment
- Load Profiles
- Fluid Sampling Results
- Previous Service History
- Manufacturer Recommendations
Not all equipment requires the same level of attention however it is important that a very comprehensive basic maintenance is completed at regular intervals to ensure failure is prevented and equipment life extended.
What Can Cause Generator Failure?
Generator Failure never happens when it’s convenient and more often than not will cause interruption to your day-to-day operations, in the most critical of operations such as hospitals generators will operate in N+1 or N+2 Configurations with UPS support.
In this case when power failure or generator failure occurs the UPS (Uninterruptible Power Supply) will support the load while the second generator starts up and takes over. Unfortunately, In applications where they are not supported by UPS or N+1 systems which is often the case in power dense sites when space is a premium they will rely on a single source of generation. When this generator fails or malfunctions this is where the disruption can occur. This doesn’t mean that systems with extended protection or complex protection don’t fail but what it does do is reduce the likelihood and increase resilience.
So what are the common causes of generator failures?
Believe it or not, critical power systems are quite resilient, let’s be honest they have to be right? They are however susceptible to human error during operation or switching operations where mistakes can be made. A lot of moving parts which include PLC’s, Controllers, Air Circuit Breakers, Fuse Carriers, Automatic Voltage Regulators, Motors, Fans, Sensors, Switches, Fuel Systems, Batteries all play their individual part in the operation and can all act as a single point of failure when not maintained correctly.
The problem with such complex systems is they require a certain level of specialist care and one of the most common causes of failure is when poor maintenance has been completed, we are an advocate of you only get what you pay for and we see it time and time again where the ‘basics’ have been completed and the ‘complex’ causes the failure.
A common issue we find is other providers ‘wrap’ the system up in one package and only focus on maintaining the engine (where they can) and forget about maintaining things such as DC tripping batteries or the main generator air circuit breaker which subsequently eventually fail.
Other common generator failures are-
- Cranking Battery Failure
- Low Fluid Levels
- External Fluid hoses Failure
- Engine Pre-heating Failure
- Battery Charger Failure
- Automatic Voltage Regulator Failure
- Catastrophic Alternator Winding Failure
- Sensor malfunction or Failure
- Controller Malfunction or complete failure
Replace VS Repair what’s right for you?
Every Generator has a predicted lifespan, some lasting longer than others but again this will all come down to how well the equipment has been maintained during its working life, when the time comes for repair, you will also have to consider the cost of a replacement. Let’s talk about the benefits of each-
Generators of all sizes are expensive and replacing them is a major consideration and investment for any business. The fundamental design of generators has not changed for many years so there still could be many years of service left in your current unit.
Reliability – generators, especially for critical standby applications, are essential items and they need to be reliable. On-going maintenance can help with this but it may come to the stage that small items are degrading and letting the system down. Refurbishment can cover all small items but the cost should be closely weighed to see if a new unit would make more sense.
Efficiency – while the fundamental mechanics have remained the same there have been some big improvements in fuel technology. This has meant engines are more efficient with lower fuel consumption and this can have a major impact on the running costs of your generator – often this is the main expense in owning a generator. If your generator is a standby only unit then this less of a consideration as the running hours will be low.
Environmental Impact – modern generators can be equipped with low emissions engines which are much less harmful to the environment. Stage IIIa or even Stage V generators are available for use in sensitive areas such as the London Ultra Low Emission zone or under the NNRM (Non-road Mobile Machinery) Directive. Again if you are using your generator as a standby unit then this may be less of a consideration.
Fuel System Installation – many older installations never considered the impact of a major diesel leak on the local environment. The regulations are now strict on the installation of diesel tanks needing to be bunded (double skinned) and tanks being fire-protected in certain circumstances. It may be that your generator installation is not in line with the current regulations and needs to be upgraded. You could be facing serious implications if your system develops a fault.
If your generator is used for standby applications, then a repair or refurbishment may be the best option – if it is used for a prime source of power then replacement of an older unit often makes sense. This of course depends on the nature of faults and the cost to repair.
Pleavin Power can provide quotations for both so you can see the best way of proceeding – the first thing we would suggest is a full generator/installation health check and report. We can undertake generator repairs, refurbishment or quote for a replacement unit and installation.
How much should maintenance cost you?
There are many different companies offering many different levels of generator servicing and maintenance throughout the UK, the truth is generator maintenance is not cheap for it to be done correctly and if all you are looking to have done is the engine filters changed then you might as well consider doing this yourself.
There is a common misconception in the Generator industry about what should and should not be done during a service visit, but the truth is nearly all manufacturers recommend the following as a minimum-
- Fluid levels checked & sampled.
- Fluids replaced every 500 hours of operation or every three years whichever occurs first.
- Engine Valve Lash Adjustment at initial 250 Hours of operation and then every 500 Hours.
- Replacement Fuel, Oil, Air and auxiliary system filters at least every six months.
- Adjustment or Replacement of Drive, Auxiliary and Fan Belts Every three years.
- Replacement of engine Thermostats and seals every three years.
- Testing of battery CCA, Charge rate and capacity.
- Integrity Check of the auxiliary fuel system, storage, and operation.
- Integrity check of Engine and alternator heaters.
- Control system inspection, connection check and functional operation.
- Connection Torque check in the generator terminal box & on the generator output breaker.
- Mechanical guards, fixings and systems check.
- Load-bank test to achieve at least 80% of rated load for four hours.
As well as the above we also complete the following-
- Megger test of windings to measure insulation resistance and track deterioration.
- Regular Fluid Sampling giving you a clear image of system health and fuel quality.
- Firmware updates and software updates for primary and auxiliary control systems.
- Tripping battery testing and switchgear maintenance.
- System functionality testing to ensure correct operation, not just an offload test.
- Black-building simulation, Supply isolation or Emergency Situation Simulation.